ANOMALOUS MUTAROTATION OF GLUCOSE 6-PHOSPHATE - AN EXAMPLE OF INTRAMOLECULAR CATALYSIS
ANOMALOUS MUTAROTATION OF GLUCOSE 6-PHOSPHATE - AN EXAMPLE OF INTRAMOLECULAR CATALYSIS
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DOI：
10.1021/bi00807a020
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发表时间：
1970-01-01
期刊：
影响因子：
2.9
通讯作者：
PENTCHEV, PG
中科院分区：
文献类型：
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作者：
BAILEY, JM;FISHMAN, PH;PENTCHEV, PG
J. M.贝利，P.H. Fishman和P.G.葡萄糖6-磷酸是由酶代谢的，最近已经证明了这些酶具有独特的异头特异性。利用还原的三磷酸吡啶核苷酸偶联葡萄糖6-磷酸脱氢酶的氧化速率测定葡萄糖6-磷酸的变旋。这种酶对异端基异构体具有特异性。在相同条件下，该变旋比旋光法测得的α D-葡萄糖的变旋快240倍。发现较高的速率不是由增加的环应变引起的，因为葡萄糖6-磷酸（21.8千卡/摩尔）的变旋活化能与D-葡萄糖（22.2千卡/摩尔）基本相同。葡萄糖的变旋
J. M. Bailey, P. H. Fishman, and P. G. Pentchev abstract: Glucose 6-phosphate is metabolized by enzymes for which distinct anomeric specificitieshave recently been demonstrated. The mutarotation of glucose 6-phosphate was mea-sured by utilizing thereduced triphosphopyridine nucleo-tide coupled rate of oxidation with glucose 6-phosphate de-hydrogenase. This enzyme is specific for the ß anomer. The mutarotation was 240 times faster thanthat of aD-glucose measured polarimetrically under the same conditions. It was found that the higher rate was not caused by increased ring strain, since the activation energy for the mutarotation of glucose 6-phosphate (21.8 kcal/mole) was essentially the same as for D-glucose (22, 2 kcal/mole). The mutarotation of glucose